MANUFACTURE OF ANISOTROPIC FERRITE MAGNET

PURPOSE:To obtain an anisotropic ferrite magnet having high residual flux density and high coercive force by using SrO.nFe2O3 (n=5.6-6.0) as a basic composition while regulating the standard deviation of the particle size distribution of raw-material iron oxide and mean particle size within specific ranges respectively. CONSTITUTION:SrO.nFe2O3 (n=5.6-6.0) is employed as a basic composition, and SiO2:0:0.1-0.5 and H3BO3: 0.05-0.2 at weight% are contained as a first crystal particle-size control agent and SiO2:0.1-1.0, CaCO3:0.5-2.0, SrCO3:0.1-1.0 and further H3BO3:0.05-0.25 as a second crystal particle-size control agent. Iron oxide having mean particle size of 0.7-0.9mum and the standard deviation of 0.14-0.16 of particle size distribution is used, powder having mean particle size of 0.7-1.2mum and a standard deviation of 0.14-0.16 for forming a temporarily baked body acquired by temporary baking at 1050-1200 deg.C is employed and formed, and main baking at 1180-1250 deg.C is conducted. Accordingly, a ferrite magnet having high Br and high iHC can be obtained easily.